Molluscum contagiosum in immunocompromised patients: AIDS presenting as molluscum contagiosum in a patient with psoriasis on biologic therapy.

Molluscum contagiosum (MC) is a common, self-limited cutaneous infection in immunocompetent individuals. However, in immunocompromised individuals the infection often has an atypical presentation and can be difficult to eradicate, making both the diagnosis and treatment challenging. Due to advancements in the management of patients with human immunodeficiency virus (HIV) and cancer, there is a growing population of immunosuppressed individuals, signaling the need for dermatologists to recognize and manage related skin diseases. We present a case of an atypical MC eruption in a patient on biologic therapy for psoriasis and an unrecognized underlying HIV infection, followed by a current review of the presentation and treatment of MC in various immunosuppressed states. With a growing population of immunosuppressed patients, it is important to recognize MC as a potential indicator of underlying immunosuppression. Testing for HIV should be offered to any patient starting immunosuppressive therapy such as biologic agents.

The molluscum contagiosum virus death effector domain containing protein MC160 RxDL motifs are not required for its known viral immune evasion functions.

The molluscum contagiosum virus (MCV) uses a variety of immune evasion strategies to antagonize host immune responses. Two MCV proteins, MC159 and MC160, contain tandem death effector domains (DEDs). They are reported to inhibit innate immune signaling events such as NF-κB and IRF3 activation, and apoptosis. The RxDL motif of MC159 is required for inhibition of both apoptosis and NF-κB activation. However, the role of the conserved RxDL motif in the MC160 DEDs remained unknown. To answer this question, we performed alanine mutations to neutralize the arginine and aspartate residues present in the MC160 RxDL in both DED1 and DED2. These mutations were further modeled against the structure of the MC159 protein. Surprisingly, the RxDL motif was not required for MC160's ability to inhibit MAVS-induced IFNß activation. Further, unlike previous results with the MC159 protein, mutations within the RxDL motif of MC160 had no effect on the ability of MC160 to dampen TNF-α-induced NF-κB activation. Molecular modeling predictions revealed no overall changes to the structure in the MC160 protein when the amino acids of both RxDL motifs were mutated to alanine (DED1 = R67A D69A; DED2 = R160A D162A). Taken together, our results demonstrate that the RxDL motifs present in the MC160 DEDs are not required for known functions of the viral protein.

Molluscum contagiosum of the eyelid: case report in a man receiving methotrexate and literature review of molluscum contagiosum in patients who are immunosuppressed secondary to methotrexate or HIV infection.

BACKGROUND: Molluscum contagiosum is a benign viral infection of the skin. Lesions typically present as dome-shaped, flesh-colored, umbilicated papules that range in size from 1 to 5 millimeters in diameter. They are usually asymptomatic, but can become tender or pruritic. Children and immunocompromised adults, including individuals being treated with immunosuppressive drugs, are most susceptible to infection. Single or multiple lesions most commonly appear on the extremities, face, genitals, and trunk. However, albeit rarely, molluscum contagiosum may also develop at other sites, including the eyelids. PURPOSE: We describe the clinical and pathologic findings of a man who developed molluscum contagiosum of the eyelid while receiving methotrexate. We also review the characteristics of other patients with molluscum contagiosum acquired either during treatment with methotrexate or associated with human immunodeficiency virus (HIV) infection and summarize the unusual sites of presentation for the viral lesions in these individuals. MATERIALS AND METHODS: The features of a man receiving methotrexate who developed molluscum contagiosum of the eyelid are presented. Using PubMed, the following terms were searched and relevant citations assessed: adalimumab, contagiosum, Enbrel, etanercept, Humira, infliximab, methotrexate, molluscum, Remicade, TNF alpha, and tumor necrosis factor alpha. In addition, the literature on methotrexate treatment and molluscum contagiosum is reviewed. RESULTS:  Several small papules were observed on the eyelid of a 24-year-old man who had been receiving methotrexate and adalimumab (Humira) for the treatment of Crohn disease. The lesions were removed by shave biopsy. Microscopic examination revealed epidermal hyperplasia composed of keratinocytes filled with large eosinophilic intracytoplasmic inclusions. Based on correlation of the clinical presentation and histopathologic findings, a diagnosis of molluscum contagiosum was established. The patient applied mupirocin 2% ointment to the biopsy sites, which subsequently healed without complication or recurrence. CONCLUSION: Molluscum contagiosum is a benign viral papular eruption that frequently affects children and immunocompromised adults. Patients treated with immunosuppressive agents, such as methotrexate, have a heightened risk of developing molluscum contagiosum lesions. It remains to be determined whether adjunct therapy with a tumor necrosis factor alpha inhibitor increasesthe risk of this viral infection. Diagnosis can usually be established by clinical presentation, although a biopsy is sometimesrequired to exclude other conditions. Molluscum contagiosum is generally self-limiting and often resolves spontaneously within18 months. However, topical (cantharidin) or locally destructive (curettage, cryotherapy, and/or laser) therapy may be indic tedfor patients who are concerned about persistent lesions and for children who are particularly susceptible to autoinoculation.

Extensive molluscum contagiosum virus infection in a young adult receiving fingolimod.

Fingolimod-related viral infections have been described on several occasions since its introduction in 2010. We hereby add a report on an otherwise immunocompetent, 18-year old Caucasian man with relapsing-remitting multiple sclerosis who developed a protracted and extensive molluscum contagiosum (MC) virus infection shortly after being started on fingolimod. Wide-spread cutaneous MC infections in adult patients are considered indicative of underlying immunosuppression. Neurologists prescribing fingolimod ought to be aware of a possibly increased risk of MC, but also need to know about its relative benignity, lack of extra-cutaneous complications, and adequate treatment options.

Immune escape phenomenon in molluscum contagiosum and the induction of apoptosis.

Molluscum contagiosum (MC) may persist for many weeks, evading host immunity. We studied the mechanism of immune escape phenomenon in MC, and the possible inducer of apoptosis. Using tissue samples of MC, we examined the numbers of epidermal Langerhans cells (LC), the expression levels of macrophage inflammatory protein-3α (MIP-3α) and thymic stromal lymphopoietin (TSLP), and the apoptotic signals. After molluscum contagiosum virus (MCV) genotyping, we studied the expression of MCV-encoded MC148 mRNA and MC159 mRNA which correspond to viral antagonist for CCR8 and viral Fas-linked interleukin (IL)-1ß converting enzyme (FLICE)-like inhibitor protein (vFLIP), respectively. The nutlin-3-induced apoptosis in MC was observed ex vivo. The numbers of CD1a(+) or Langerin(+) epidermal LC and the expression levels of MIP-3α were markedly decreased in MC. The expression of TSLP was enhanced in the lesional epidermis of atopic dermatitis and human papillomavirus-induced warts, whereas the expression was observed locally in MC. All 14 MC samples examined harbored MCV type 1. The MC148 mRNA was detected in all 14 samples and the MC159 mRNA was detected in 13 samples. Apoptotic cells were absent or at a background level in the living layers of MC, but their numbers were increased in the molluscum bodies by overnight incubation with 5 µmol/L nutlin-3 in culture medium. In conclusion, molluscum bodies are protected from host immune responses and apoptotic signals by being surrounded by LC-depleted epidermal walls and viral immunosuppressive molecules, but could be eradicated by reagents inducing p53-dependent apoptosis.

Inhibition of interferon gene activation by death-effector domain-containing proteins from the molluscum contagiosum virus.

Apoptosis, NF-κB activation, and IRF3 activation are a triad of intrinsic immune responses that play crucial roles in the pathogenesis of infectious diseases, cancer, and autoimmunity. FLIPs are a family of viral and cellular proteins initially found to inhibit apoptosis and more recently to either up- or down-regulate NF-κB. As such, a broad role for FLIPs in disease regulation is postulated, but exactly how a FLIP performs such multifunctional roles remains to be established. Here we examine FLIPs (MC159 and MC160) encoded by the molluscum contagiosum virus, a dermatotropic poxvirus causing skin infections common in children and immunocompromised individuals, to better understand their roles in viral pathogenesis. While studying their molecular mechanisms responsible for NF-κB inhibition, we discovered that each protein inhibited IRF3-controlled luciferase activity, identifying a unique function for FLIPs. MC159 and MC160 each inhibited TBK1 phosphorylation, confirming this unique function. Surprisingly, MC159 coimmunoprecipitated with TBK1 and IKKε but MC160 did not, suggesting that these homologs use distinct molecular mechanisms to inhibit IRF3 activation. Equally surprising was the finding that the FLIP regions necessary for TBK1 inhibition were distinct from those MC159 or MC160 regions previously defined to inhibit NF-κB or apoptosis. These data reveal previously unappreciated complexities of FLIPs, and that subtle differences within the conserved regions of FLIPs possess distinct molecular and structural fingerprints that define crucial differences in biological activities. A future comparison of mechanistic differences between viral FLIP proteins can provide new means of precisely manipulating distinct aspects of intrinsic immune responses.

Histopathological study of cutaneous manifestations in HIV and AIDS patients.

OBJECTIVES: Most human immunodeficiency virus (HIV)-infected patients develop various skin diseases. These skin manifestations not only act as markers but also reflect the patient's underlying immune status. Investigating CD4 counts is costly and not always possible. Thus, the potential value to be gained by using skin manifestations as predictors of low CD4 counts and disease progression should be explored. The present study attempted to correlate the association of various cutaneous disorders found in HIV patients with CD4 and CD8 counts, the CD4 : CD8 ratio and stage of HIV infection. METHODS: This was a prospective study involving 61 patients who were HIV-positive and demonstrated skin lesions. Punch biopsies of skin were taken for histopathological diagnosis. CD4 and CD8 T cell counts were performed. RESULTS: The study sample included a majority of male patients, most of whom were aged 21-40 years. Pruritic papular dermatitis was the most common skin manifestation, followed by molluscum contagiosum, eosinophilic folliculitis, and Hansen's disease. Most of the lesions were associated with CD4 counts of <220/µl (n = 38). All skin lesions associated with HIV or acquired immune deficiency syndrome (AIDS) showed a CD4 : CD8 ratio of <0.50. CONCLUSIONS: The study findings demonstrate an inverse relationship between CD4 counts and the occurrence of skin lesions. The majority of lesions were associated with stage 3 or stage 4 infection. Thus, specific cutaneous manifestations can be considered as good clinical indicators for predicting underlying immune status in resource-poor countries.

Aberrant humoral immune reactivity in DOCK8 deficiency with follicular hyperplasia and nodal plasmacytosis.

Mutations in the DOCK8 gene define the most common form of autosomal-recessive Hyper-IgE-syndrome (AR-HIES/OMIM#243700). In a patient with extensive molluscum contagiosum lesions, a homozygous DOCK8 gene deletion was demonstrated. In-vivo 18-FDG uptake showed multiple non-enlarged lymph nodes without uptake in the spleen. Lymph node biopsies for subsequent immunohistochemistry showed clear differences with the mouse model of DOCK8 deficiency in which these mice show no GCs. Unexpectedly, the patient's lymph nodes demonstrated lymphocyte polyclonality, follicular hyperplasia and an unusual IgE(+) plasma cell expansion. In contrast, the proliferative capacity of circulating B-cells was almost absent with little in-vitro Ig production or plasmablast formation. Also the T-cell proliferation indicated a partial defect. Hematopoietic stem cell transplantation (HSCT) was performed resulting in the disappearance of the molluscum contagiosum lesions. In sum, DOCK8 deficiency results in defective antibody responses and undirected plasma cell expansion in the lymph nodes, as part of a combined immunodeficiency cured by HSCT.

Atypical molluscum contagiosum accompanied by CD30-positive lymphoid infiltrates.

Atypical presentations of molluscum contagiosum require histophathologic examination and may show pleomorphic lymphocytic infiltrates of a reactive nature, mimicking cutaneous lymphoproliferative diseases. Serial sections of specimens or polymerase chain reactions to show T-cell receptor clonality may be helpful for differential diagnosis. We report a case of atypical molluscum contagiosum accompanied by atypical lymphocytic infiltration showing CD30 positivity.

Immunolocalization of toll-like receptor 2 in viral warts and molluscum contagiosum.

OBJECTIVE: To explore toll-like receptor 2 (TLR2) immunolocalization and its possible role in the innate immune response against viral warts and molluscum contagiosum (MC). STUDY DESIGN: Using standard immunohistochemical techniques, we examined 50 cases (25 cases with viral warts and 25 cases with MC) together with normal skin biopsies of 25 age and sex-matched subjects who comprised the control group. RESULTS: TLR2 was expressed in the epidermis of all controls and in 94% of study cases. Staining patterns were cytoplasmic, membranous, nuclear and combined. There was a significant difference between cases and controls regarding the intensity (p = 0.0001) and pattern (p = 0.001) of TLR2 expression, where intense expression was in favor of cases and membranous and nuclear pattern of staining was seen only in cases. The intensity of TLR2 expression was significantly associated with patients of young age (p = 0.04), short disease duration (p = 0.04), facial location (p = 0.009), and MC category (p = 0.02). CONCLUSION: Our study suggests that upregulation of TLR2 is involved in the induction of defense mechanism against human papillomavirus and MC virus. Its nuclear localization may be related to virus pathogenesis, virus-TLR interaction, or to other unknown molecular events.

Conversion from tacrolimus/mycophenolic acid to tacrolimus/leflunomide to treat cutaneous warts in a series of four pediatric renal allograft recipients.

BACKGROUND: The challenge of immunosuppression in pediatric renal transplantation is to balance preventing rejection while avoiding infectious complications. A dermatological complication of immunosuppression is viral warts, which cause significant disfigurement and increase the risk of skin malignancy. METHODS: We present three pediatric and adolescent renal allograft recipients with multiple, recalcitrant verrucae vulgares lesions and one patient with molluscum contagiosum who were switched from mycophenolate mofetil to leflunomide. Teriflunomide metabolite levels were carefully maintained between 50,000 and 100,000 ng/mL to balance its immunosuppressive and antiviral properties. No adverse events requiring discontinuation of leflunomide were encountered. RESULTS: Switching from mycophenolate mofetil to leflunomide successfully cleared verrucae vulgares and molluscum lesions in all four renal transplant patients. CONCLUSIONS: The ability to minimize and even resolve warts can improve quality of life by reducing risk of skin malignancies and emotional distress in solid organ transplant patients. Leflunomide is a potential therapeutic option for posttransplantation patients with skin warts because it serves both as an adjunct to the immunosuppressive regimen and an antiviral agent.

Letter: Human papilloma virus and molluscum contagiosum lesions related to infliximab therapy for psoriasis: a case series.

INTRODUCTION: Biological therapy for psoriasis exerts its action via an immunomodulatory and eventually immunosuppressive mode. Immunosuppression is linked to HPV flares. Our purpose is to investigate a possible relationship between infliximab therapy for psoriasis and human papilloma virus and molluscum (HPV/MC) infections. METHODS: We report a case series of three patients with psoriasis on infliximab, who developed HPV/MC lesions following their treatment. RESULTS: Our patients developed HPV/MC lesions within a few months after the initiation of infliximab infusions for psoriasis. DISCUSSION: Immunosuppresion is related to HPV/MC flares. Biological therapy and in particular infliximab treatment acts by immunomodulation and eventually a degree of immunosuppression. CONCLUSIONS: Anti-TNF treatment could be associated with HPV and/or MC flares. For this reason, we suggest the consideration of obtaining a routine cervical PAP smear before the commencement and during treatment with anti-TNF agents for psoriasis.

The MC159 protein from the molluscum contagiosum poxvirus inhibits NF-κB activation by interacting with the IκB kinase complex.

Molluscum contagiosum virus (MCV) causes persistent neoplasms in healthy and immunocompromised people. Its ability to persist likely is due to its arsenal of viral immunoevasion proteins. For example, the MCV MC159 protein inhibits TNF-R1-induced NF-κB activation and apoptosis. The MC159 protein is a viral FLIP and, as such, possesses two tandem death effector domains (DEDs). We show in this article that, in human embryonic kidney 293 T cells, the expression of wild-type MC159 or a mutant MC159 protein containing the first DED (MC159 A) inhibited TNF-induced NF-κB, or NF-κB activated by PMA or MyD88 overexpression, whereas a mutant protein lacking the first DED (MC159 B) did not. We hypothesized that the MC159 protein targeted the IκB kinase (IKK) complex to inhibit these diverse signaling events. Indeed, the MC159 protein, but not MC159 B, coimmunoprecipitated with IKKγ. MC159 coimmunoprecipitated with IKKγ when using mouse embryonic fibroblasts that lack either IKKα or IKKß, suggesting that the MC159 protein interacted directly with IKKγ. MC159-IKKγ coimmunoprecipitations were detected during infection of cells with either MCV isolated from human lesions or with a recombinant MC159-expressing vaccinia virus. MC159 also interacts with TRAF2, a signaling molecule involved in NF-κB activation. However, mutational analysis of MC159 failed to reveal a correlation between MC159-TRAF2 interactions and MC159's inhibitory function. We propose that MC159-IKK interactions, but not MC159-TRAF2 interactions, are responsible for inhibiting NF-κB activation.

An inflammatory reaction surrounding molluscum contagiosum as possible manifestation of immune reconstitution inflammatory syndrome in HIV infection.

Highly active antiretroviral therapy can restore specific immune responses and control of microorganism infections in human immunodeficiency virus-positive patients. This immune recovery may cause an inflammatory reaction to microbial and autoimmune antigens known as immune reconstitution inflammatory syndrome. We describe a clinical case with an intense inflammatory response surrounding molluscum contagiosum after highly active antiretroviral therapy. The clinical and laboratory findings suggested that the reaction was due to immune reconstitution inflammatory syndrome occurring during a period of immune recovery in a child with acquired immune deficiency syndrome.

Molluscum contagiosum involving an epidermoid cyst with xanthogranuloma-like reaction in an HIV-infected patient.

BACKGROUND: Molluscum contagiosum (MC) causes characteristic cutaneous lesions that occur mainly in children, sexually active adults, and immunocompromised individuals, especially those with human immunodeficiency virus (HIV) infection. Patients infected with HIV, particularly those with advanced disease, have an increased incidence, up to 33.3%, of MC in non-anogenital areas. MC has been rarely found to be associated with epidermoid cysts. CASE REPORT: A 44-year-old male with HIV infection presented with the complaint of a-3-month history of a tender nodule on the left neck. H&E stained sections showed a ruptured cyst, lined with squamous epithelium showing cytopathic changes of MC, and a xanthogranuloma-like inflammatory reaction with characteristic Touton-type giant cells. CONCLUSION: MC infections are common, however MC associated with epidermoid cysts is infrequent. A few cases of MC occurring in epidermoid cysts have previously been reported. We are presenting a case of MC involving an epidermoid cyst in an AIDS patient, with a unique xanthogranuloma-like reaction. Xanthogranulomatous (XG) reactions have been infrequently reported in association with other viral infections, however, poxvirus-associated XG reaction has only been observed in animals. This is the first reported case of MC-associated XG reaction in humans.